Plasma degradation of organic compounds: oxidation of oxalic and maleic acid

Solid oxalic and maleic acid pellets are exposed to an inductively coupled oxygen plasma to investigate the oxidizing properties of the plasma on organic powders in view of ageing studies. Both acids degrade to carbon dioxide according to pseudo 1st order reactions with kinetic constants k 0.250 min-1 and k = 0.098 min-1 respectively, relevant to the experimental conditions. Models involving the oxygen atoms present in the plasma phase are proposed for the degradation mechanism. (author)